Improvements to openvr code

- Overlays are implemented (sans input for the moment)
- Fixed a problem where the movemanager was using the wrong values for hmd rotation & position

Engine/source/gfx/bitmap/gBitmap.cpp

@@ -293,6 +293,7 @@ void GBitmap::allocateBitmap(const U32 in_width, const U32 in_height, const bool
       break;
      case GFXFormatR8G8B8:       mBytesPerPixel = 3;
       break;
+     case GFXFormatR8G8B8A8_LINEAR_FORCE:
      case GFXFormatR8G8B8X8:
      case GFXFormatR8G8B8A8:     mBytesPerPixel = 4;
       break;